MANILA (2nd UPDATE) - A bank executive allegedly forged signatures and breached protocols to defraud one of the country's largest lenders, National Bureau of Investigation officials said Friday.

The suspect, Maria Victoria Lopez, was arrested on July 18 after she allegedly attempted to shift P2.25 million in interest from unauthorized loans, officials said.

Lopez was presented to reporters wearing an orange detainee's shirt and with her face wrapped with a shawl.

The interest payment was for one of 2 borrowings from a P25-billion pool. The bank's client, which was authorized to borrow from the fund, denied executing the 2 loans worth P900 million and P850 million, officials said.

The NBI did not name Metrobank, the country's largest lender, which on Friday confirmed the arrest of an individual for alleged fraud. The bank's admission came after the Philippine Daily Inquirer reported the case.

"The biggest loss on this is the integrity of the banking system and the internal control system of the bank," said NBI spokesman Ferdinand Lavin, adding authorities were "doing everything" to safeguard the industry.

Bangko Sentral ng Pilipinas (BSP) Deputy Governor Chuchi Fonacier meanwhile assured that the incident is an "isolated case" and that the banking system is "well-capitalized."

"Metrobank is a big bank. It can handle the situation," Fonacier told reporters.

Lopez had worked for the bank for 3 decades and was earning around P250,000 per month as head of corporate services. She could be tried for qualified theft, falsification of documents and violation of banking laws, officials said.

"She's not cooperating. She's not talking," Lavin said, adding an investigation was underway to determine if other people were involved.

Lopez allegedly directed the issuance of a manager's check to an individual, a "red flag" because such checks are issued only to corporate clients, said Norman Aguirre, the NBI agent on case.

"There were irregularities in the documents itself, indicating falsification such as different fonts, dubious signatures," Aguirre said.

"The bank conducted an internal inquiry, confirmed that the client has a loan with the bank or if they have draw-downs. Much to their dismay, they discovered such loans were unknown to the client," he said.

BSP Governor Nestor Espenilla said regulators were investigating the fraud, the latest in a wave of controversies to hit the banking system since last year.

Espenilla said he expected the lender, controlled by taipan George Ty, to be "resilient."

In February 2016, unidentified hackers shifted $81 million from Bangladesh's foreign reserves to an RCBC branch in Makati City.

The BSP fined the Yuchengco-owned lender a record P1 billion over the incident, which exposed the vulnerabilities of the financial system to money laundering.

Legislators also recently investigated local banks over glitches.
Last month, Bank of the Philippine Islands' digital channels were paralyzed for 2 days due to what it said was an "internal error."

The country's largest lender, BDO Unibank, later admitted that 7 of its ATMs were "compromised" in a "skimming" attack that allowed unauthorized transactions.